1. Field of Invention
The present invention relates to an invisible passenger airbag door, and more particularly, to an invisible passenger airbag door capable of preventing the deterioration of an external appearance due to a line constructed of micro holes defining an airbag door that is formed by processing the micro holes on an instrument panel to define an incision portion, and preventing a phenomenon of tear of the instrument panel off the line upon deployment of the airbag in a case where the depths of or intervals between the micro holes are not proper.
2. Description of the Prior Art
Generally, passenger restraint systems that are employed in automobiles etc. to ensure the safety of passengers include seat belts, airbag systems, and the like.
The airbag system is to prevent the head of a driver or passenger from colliding against a front structure in an interior passenger room of an automobile due to inertia upon occurrence of an automobile accident. As shown in FIG. 1, a driver airbag 1 for protecting a driver, and a passenger airbag 2 for protecting an occupant in a front passenger seat are commonly used. A side airbag 3 is also used for coping with a side impact in an automobile, if necessary.
In such an airbag system, the driver airbag 1 is mainly installed in the center of a steering wheel, while the passenger airbag 2 is installed by placing an airbag module behind the instrument panel. Thus, an additional door is constructed by forming an incision line in the instrument panel so that the door can be easily opened upon operation of the passenger airbag 2.
Recently, there is a tendency for such a door for the passenger airbag 2 to be constructed in an invisible type so that an indication of the installation of the passenger airbag 2 cannot be seen from the outside to prevent aesthetic deterioration. In this case, micro holes 5a are formed using a laser or mechanically in a portion of a surface of the instrument panel 4 corresponding to the airbag door, as shown in FIGS. 2 and 3. Although the micro holes cannot be normally identified from the outside, an incision portion 5 constructed of the processed micro holes 5a is incised and the airbag is then inflated when the airbag is operated due to the occurrence of an impact. In FIG. 3, an upper surface corresponds to an outer surface of the instrument panel 4 viewed by an occupant.
In a case where the depths of the micro holes become large or the intervals between the micro holes become small upon processing the micro holes in such a conventional passenger airbag door, however, there is a problem in that an incision line constructed of the micro holes for defining the incision portion may be seen from the outside.
Further, if the depths of and intervals between the micro holes are not proper, it is likely that the instrument panel may be torn at portions thereof off the incision line defining the incision portion when the airbag is deployed. There is a high probability of the occurrence of such a phenomenon, particularly at low temperature.